The present invention relates to a method of creating animation and a computer readable program. More particularly, the invention relates to a method for creating images by use of computer-based image processing software dealing with two-dimensional shapes, as well as to a method for creating two-dimensional animation.
A polygon such as the one in FIG. 8A is created by conventional drawing software as follows: vertices are established one after another by use of a mouse to form a polygon. The color and transparency of the polygon are then set. If colors or other parameters vary from one portion to another in the polygon, polygons sharing vertices therebetween are created separately as shown in FIG. 8B (920, 946, 947, 948, 951, 949) and are later overlaid for display.
The conventional technique outlined above involves addressing a large number of overlaid vertices (930-945, 941-943, 931-938, 936, 950, 929). Careful work is required to get the vertices in complete agreement. In the case of a global movement or rotation of such polygons, all overlaid vertices must be moved or rotated in unison. The trouble in animation is that these vertices tend to deviate from one another during such transition.
It is therefore an object of the present invention to provide a method for creating a polygon having divisions formed inside without duplicate setting of overlaid vertices spanning such divisions.
In carrying out the invention and according to one aspect thereof, there is provided a method whereby a base polygon A is first created conventionally. The inside of the base polygon A is divided into a plurality of regions by first selecting one vertex of the base polygon A. A polyline is drawn continuously starting from the selected vertex inside the base polygon A with new vertices set thereon. As the end point of the polyline, another vertex of the base polygon A is selected. When the base polygon is divided by the polyline, the two divided regions are stored.
Other objects,. features and advantages of the invention will become more apparent upon a reading of the following description and appended drawings.